#refrigerant

As we often do in these tech tips, we will start with the common and more practical explanation of saturation and then move to the more technical and nerdy explanation later. When we say “at saturation” or “saturated” in the HVAC/R trade, we are generally referring to the refrigerant that is in the process of […]

Before I start on this one… At HVAC School, we focus on a wide range of topics. Many of them are very basic. My experience as a trainer for over 16 years has taught me that no matter what I assume others SHOULD know, it doesn't change the fact that they often do not. This […]

There has never been a more complicated and confusing time surrounding refrigerants than what we are in right now. We are seeing flammable HC (hydrocarbon) refrigerants with increasing regularity, and EPA rules that just changed appear to be changing again. With all this tumultuous change, it's important to know what to look for in refrigerants […]

Pump down solenoid valves are commonplace for any refrigeration technician. They are energized with the compressor still running, shutting off flow in the liquid line so that the refrigerant is pumped into the condenser and receiver. The compressor will then shut off once a low-pressure switch opens the circuit when the pressure falls below a […]

Suction pressure, head pressure, subcooling, superheat, delta T. Taking all five of these calculations into account on every service call is critical. Even if you must do further diagnostic tests to pinpoint the problem, these five factors are the groundwork before more effective diagnostics can be done. I would also add static pressure as an […]

We all see a lot of questions about dyes, leak stoppers, lubricants, inhibitors, and snake oil. All of those were designed to go into the refrigerant circuit and “improve” something. I just go back to what Ray Johnson always said. (Ray is one of my early heroes in the biz, and he taught me a […]